private int WriteHeader(string filename, DateTime? modificationTime, CompressionInfo compressionInfo = null)
{
var explicitZipCompressionInfo = compressionInfo != null ? new ZipCompressionInfo(compressionInfo) : this.zipCompressionInfo;
byte[] encodedFilename = ArchiveEncoding.Default.GetBytes(filename);
OutputStream.Write(DataConverter.LittleEndian.GetBytes(ZipHeaderFactory.ENTRY_HEADER_BYTES), 0, 4);
if (explicitZipCompressionInfo.Compression == ZipCompressionMethod.Deflate)
{
OutputStream.Write(new byte[] {20, 0}, 0, 2); //older version which is more compatible
}
else
{
OutputStream.Write(new byte[] {63, 0}, 0, 2); //version says we used PPMd or LZMA
}
HeaderFlags flags = ArchiveEncoding.Default == Encoding.UTF8 ? HeaderFlags.UTF8 : (HeaderFlags)0;
if (!OutputStream.CanSeek)
{
flags |= HeaderFlags.UsePostDataDescriptor;
if (explicitZipCompressionInfo.Compression == ZipCompressionMethod.LZMA)
{
flags |= HeaderFlags.Bit1; // eos marker
}
}
OutputStream.Write(DataConverter.LittleEndian.GetBytes((ushort) flags), 0, 2);
OutputStream.Write(DataConverter.LittleEndian.GetBytes((ushort)explicitZipCompressionInfo.Compression), 0, 2); // zipping method
OutputStream.Write(DataConverter.LittleEndian.GetBytes(modificationTime.DateTimeToDosTime()), 0, 4);
// zipping date and time
OutputStream.Write(new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, 0, 12);
// unused CRC, un/compressed size, updated later
OutputStream.Write(DataConverter.LittleEndian.GetBytes((ushort) encodedFilename.Length), 0, 2); // filename length
OutputStream.Write(DataConverter.LittleEndian.GetBytes((ushort) 0), 0, 2); // extra length
OutputStream.Write(encodedFilename, 0, encodedFilename.Length);
return 6 + 2 + 2 + 4 + 12 + 2 + 2 + encodedFilename.Length;
}
private int WriteHeader(string filename, DateTime? modificationTime)
{
byte[] encodedFilename = ArchiveEncoding.Default.GetBytes(filename);
OutputStream.Write(BitConverter.GetBytes(ZipHeaderFactory.ENTRY_HEADER_BYTES), 0, 4);
OutputStream.Write(new byte[] {63, 0}, 0, 2); //version
HeaderFlags flags = ArchiveEncoding.Default == Encoding.UTF8 ? HeaderFlags.UTF8 : (HeaderFlags)0;
if (!OutputStream.CanSeek)
{
flags |= HeaderFlags.UsePostDataDescriptor;
if (compression == ZipCompressionMethod.LZMA)
{
flags |= HeaderFlags.Bit1; // eos marker
}
}
OutputStream.Write(BitConverter.GetBytes((ushort) flags), 0, 2);
OutputStream.Write(BitConverter.GetBytes((ushort) compression), 0, 2); // zipping method
OutputStream.Write(BitConverter.GetBytes(modificationTime.DateTimeToDosTime()), 0, 4);
// zipping date and time
OutputStream.Write(new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, 0, 12);
// unused CRC, un/compressed size, updated later
OutputStream.Write(BitConverter.GetBytes((ushort) encodedFilename.Length), 0, 2); // filename length
OutputStream.Write(BitConverter.GetBytes((ushort) 0), 0, 2); // extra length
OutputStream.Write(encodedFilename, 0, encodedFilename.Length);
return 6 + 2 + 2 + 4 + 12 + 2 + 2 + encodedFilename.Length;
}
